It may happen that an employee starts at the end of the month after the salaries have been paid and you want to pay the days in question in the following month.
Since the program stores the insurance and withholding tax codes for each person each month, one cannot simply add the amounts in the new month without processing the month of entry. The program would only consider this first month for the calculations of the ceilings and withholding tax, and the calculations could therefore be wrong.
In fact, no salary corresponds to a vacuum, whereas a salary of 0.-- corresponds to a salary.
The dates taken into account for the caps and the withholding tax period will then be correct.